Open AccessMonte Carlo‐based investigation of absorbed‐dose energy dependence of radiochromic films in high energy brachytherapy dosimetry
Author(s) -
Subhalaxmi Mishra,
Selvam T. Palani
Publication year - 2014
Publication title -
journal of applied clinical medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.83
H-Index - 48
ISSN - 1526-9914
DOI - 10.1120/jacmp.v15i1.4448
Subject(s) - dosimetry , monte carlo method , brachytherapy , absorbed dose , materials science , medical physics , physics , nuclear medicine , computational physics , medicine , mathematics , radiation therapy , statistics , radiology
Relative absorbed dose energy response correction, R, for various radiochromic films in water phantom is calculated by the use of the Monte Carlo‐based EGSnrc code system for high energy brachytherapy sources60 Co ,137 Cs ,192 Ir and169 Yb . The corrections are calculated along the transverse axis of the sources (1‐15 cm). The radiochromic films investigated are EBT, EBT2 (lot 020609 and lot 031109), RTQA, XRT, XRQA, and HS. For the60 Co source, the value of R is about unity and is independent of distance in the water phantom for films other than XRT and XRQA. The XRT and XRQA films showed distance‐dependent R values for this source (the values of R at 15 cm from the source in water are 1.845 and 2.495 for the films XRT and XRQA, respectively). In the case of137 Cs and192 Ir sources, XRT, XRQA, EBT2 (lot 031109), and HS films showed distant‐dependent R values. The rest of the films showed no energy dependence (HS film showed R values less than unity by about 5%, whereas the other films showed R values higher than unity). In the case of169 Yb source, the EBT film showed no energy dependence and EBT2 film (lot 031109) showed a distance‐independent R value of 1.041. The rest of the films showed distance‐dependent R values (increases with distance for the films other than HS). The solid phantoms PMMA and polystyrene enhance the R values for some films when compared the same in the water phantom. PACS number: 87.53.Jw